its still the wrong stuff and wrong advice im afraid if any of the jointing compounds were to be used the best would be joint cement as its light and sands down 20 times easier its also a finish coat meaning you will get a nice finish on it, joint filler was never meant to be used as a finish, youve also stated that the wall paper was stuck to the wall like cement? and you couldn't get it off no matter how hard you tried? yet you think the weight of 2-3 mil of skim will pull it off? people say you shouldn't skim over wall paper but i've known it to be successful, at the end of the day if it was my ceiling i would have scraped the lot off no matter how hard it was, and have done so to my place even taking room fulls of of old skim off , your never going to get a good finish with filler on a whole ceiling even after rubbing it down, roughcaster has suggested using a pro lite mix over the top you could try that but you are still going to have to rub it down.
